Sight

• US 5,534,696 A
• Filed: 12/05/1994
• Issued: 07/09/1996
• Est. Priority Date: 12/16/1993
• Status: Expired due to Fees

• Current Assignee: Celsiustech Electronics AB
• Original Assignee: Celsiustech Electronics AB
• Inventors: Johansson, Stefan, Sandstrom, Unto
• Primary Examiner(s): Hannaher, Constantine
• Application Number:
  US08/353,275
• Time in Patent Office: 582 Days
• Field of Search: 250/330, 250/334
• US Class Current: 250/330
• CPC Class Codes: G02B 23/12 with means for image conversion or intensification

Abstract

A sight apparatus has a day-sight part, a night-sight part and a filter which quenches the visible light so that the night-sight part in the form of an IR sight can be used during the daytime as well. In order to improve use of the night-sight under daylight conditions the filter has characteristics which quench visible light having wavelengths outside the wavelengths of blue light and is arranged in the beam path for the incoming visible light.

Claims

1. A sight apparatus comprising:

an IR camera which converts thermal radiation coming in towards the opening of the IR camera into a visible image;

a sight part for incoming visible light;

means for guiding the image generated by the IR camera into the beam path for the incoming visible light; and

at least one filter with a filter characteristic which quenches visible light having wavelengths outside the wavelengths of blue light, said filter being arranged to be introduced into the beam path for the incoming visible light whereby said blue light is transmitted along with said image generated by said IR camera towards said sight part.

2. A sight apparatus according to claim 1, wherein said filter consists of a so-called BG glass.

3. A sight apparatus according to claim 1, wherein said filter exhibits a filter characteristic having a first quenching level within the wavelength range for blue light and a second quenching level, which is much higher in relation to the first quenching level, for visible light outside the wavelengths of blue light.

4. A sight apparatus according to claim 1, wherein said filter is pivotably introduced into the beam path.

5. A sight apparatus according to claim 1, wherein said filter is displaceably introduced into the beam path.

6. A sight apparatus according to claim 1, wherein said filter includes a number of filter elements which can be introduced into the beam path for the incoming visible light.

7. A sight according to claim 6, wherein said filter elements are adapted to be separately introduced into the beam path.

8. A sight apparatus comprising:

an IR camera which converts thermal radiation coming in through the opening of the IR camera into a visible image;

a sight part for incoming visible light;

means for guiding the image generated by the IR camera into the beam path for the incoming visible light;

at least one filter with a filter characteristic which quenches visible light having wavelengths outside the wavelengths of blue light; and

means for removably placing filter into the beam path for the incoming visible light, whereby said blue light can be transmitted along with said image generated by said IR camera towards said sight part.

9. A sight apparatus according to claim 8 further including another filter element adapted to be removably placed into the beam path for quenching visible daylight.